another 'fresh out of play school' question concerning legalization

[Andrew]

can anyone comment on this please...., and sorry if it's been asked before,

If I were to add a frog style 24v battery to a MP would it make the bike road legal in the UK(assuming it will not exceed or is limited to 15mph)?  Or does the size of the motor still fail to meet legal criterias?  

I'm thinking that having a 24v and a 48v battery for different circumstances could be a solution as the motor can have the voltage changed via USB.

Would it be a matter of just swapping over the battery and changing motor voltage(plug n play).... or am I missing something?


Andrew

[MonkeyMagic]

Hey mate

I know the max motor output is supposed to be 250W for EU and the max speed (I think PAS) is 25km/h

Highly doubt any person with authority to fine you has any testing equipment to test your output so as long as you abide by the road rules and speed limit you should be fine

Its 200W max in Australia arghh!!! lol

[Andrew]

ha ha!

That's the kind of answer I like to hear!  

But just out of interest, if it can be done simplyand it is possible to drive the MP motor with a frog style 24v10ah I wonder what ranges and mph you would get

[MonkeyMagic]

I'm tipping about 15-18mph top speed and around 15 miles at full throttle. yay

[Andrew]

good back up plan for the future, if laws eventually get tightened up 

[Leslie]

I think some should make some XXX~X watt stickers and put them on sale.  Will sell like hot cakes.

[Andrew]

I think some should make some XXX~X watt stickers and put them on sale.  Will sell like hot cakes.

not a bad idea


I'm having a custom made tarpaulin PVC cover with elastic pull string made for my GM battery. That and panieer bags on the rear will hopefully hide lots of wires and at least 'a piece' of the pie.  I have also looked into the idea of fitting an Aero disc as on racing bikes to cover the motor, but i'm sure this has it's own complications.

[Leslie]

Andrew if you get the program cable you can make your MP legal enough with a 36v~48v pack.

The 36v pack will give you more range.  The MP, Its got speed control and max and minimum current settings.

The max peak currents can have the low efficiency so you may consider 150% your max current and 120% more constant current than 250 watt multiplies to.


Say at 42v divide max current by 150%*250 watts, 375 watts max / 42v = 8.9 amps max and at 120% 300 watts continuous = 7.1 amps cont.

Set your forward speed to around 96% to limit you speed assist to 25kph

considering motor inefficiencies you can set your controller to do more than 250 watts on any voltage battery and still be legal.  Just a ball park guess any where between 50% inefficiency to 80% is the zone that I think matters to legality.

Need to consider gearless direct drive motors inefficiency during take offs.  They are very efficient in cruise but can go as low as 25% inefficient.

[Andrew]

thanks for the info. Yes I do have the USB cable so will be able to alter as you've mentioned.  Just need to get hold of the new rim first adn then the experiments can start taking place!  been promised it on two occaqsions but still nothing. Supposedly now coming on Wednesday this week 

[Leslie]

Yes the cable is cool but it is not accurate on both my pies, I had to add a shunt in the controller to calibrate the current flow closer to the software setting.
http://cgi.ebay.com.au/Digital-Clamp-Meter-Multimeter-Tester-LCD-Amp-Ohm-AC-DC-/110583227441?pt=AU_B_I_Electrical_Test_Equipment&hash=item19bf462431




One person bought an digital clamp amp meter like this and it worked well enough to set his controller.  This is a cheap solution that requires no installation.

Weighing in at around $24 USD is the Tunigy Watt Meter.  This is a neat device that just requires you to hook it up and has a warning alarm system that is user definable.

Then as you know there is the Cycle Analyst that comes with ways to measure both wheel speed and power usage and spits out some usefull data on to the screen.  There awe a few things you casn play with like the throttle controll and what not.